Quinupristin/dalfopristin, or quinupristin-dalfopristin, (pronunciation: kwi NYOO pris tin / dal FOE pris tin) (trade name Synercid) is a combination of two antibiotics used to treat infections by staphylococci and by vancomycin-resistant Enterococcus faecium.
Quinupristin and dalfopristin are both streptogramin antibiotics, derived from pristinamycin. Quinupristin is derived from pristinamycin IA; dalfopristin from pristinamycin IIA. They are combined in a weight-to-weight ratio of 30% quinupristin to 70% dalfopristin.
Administration
Intravenous, usually 7.5 mg/kg every 8 hours (infections/life threatening VRSA); every 12 hours (skin infections).
No renal dosing adjustments, hepatic dosing adjustments are not defined, consider reducing dose.
Quinupristin binds to a nearby site on the 50S ribosomal subunit and prevents elongation of the polypeptide,[1] as well as causing incomplete chains to be released.[1]
Pharmacokinetics
Clearance by the liver CYP450:3A4 inhibitor, half-life quinupristin 0.8 hours, dalfopristin 0.7 hours (with persistence of effects for 9–10 hours).
Manzella JP (December 2001). "Quinupristin-dalfopristin: a new antibiotic for severe gram-positive infections". American Family Physician. 64 (11): 1863–6. PMID11764864..